a study of the quality of a local herbal tea and volatiles of parinari ...

3.2 Sample Treatment
Fruit and vegetable samples were cleaned after collection to reduce the microbial load.
Selection was done to remove damaged, discoloured and contaminated samples. Some of
the cocoyam and cassava leaves were dried at 24 0 C for 10 days and stored in sacks. S.
cocculoides fruits were cracked just before analysis to collect the pulp. P. curatellifolia
fruits were peeled and the pulp was scrapped off using a sharp knife.
3.3 Chemicals, reagents and apparatus
Chemicals and reagents used in this study were of analytical grade. n-Alkane standards
were purchased from Sigma Aldrich (Pretoria, South Africa) whereas dichloromethane,
methanol, n-hexane, sodium chloride and Sodium hydrogen carbonate were purchased
from Merck Chemicals (Johannesburg, South Africa). Oxalic acid and sodium sulphate
were purchased from Saarchem (Johannesburg, South Africa) and antibumping granules
from BDH Chemicals (Johannesburg, South Africa).
The following apparatus and equipment were used; Clevenger apparatus purchased from
Sigma Aldrich (Johannesburg, South Africa), Cold Finger glassware purchased from
Sigma Adrich (Johannesburg, South Africa), Knf Neuberger laboport vacuum pump
(1.0bars) (Johannesburg, South Africa), steam distillation unit purchased from Sigma
Aldrich (Pretoria, South Africa), 30cm vigreux column, Solid Phase Microextraction
(SPME) Device (5mm, 100µm) PDMS (SUPELCO) purchased from Sigma Aldrich
(Pretoria, South Africa), gas chromatograph-mass spectrometer (GC-MS) (GC Agilent
6890N system coupled directly to a 5973 MS detector). The ELISA machine used was a
Microtiter plate reader (Multiskan Ascent; Thermo Labsystems; USA)
38